Yamaha 1990 ?? Big Bear 350 4x4 Oil Filter bolts-cannot remove

[quintain]

Hi

This bike is fighting me at every turn.

2 of the 3 allen key bolts holding the oil filter cover are stuck.

They have an internal 6mm key which has been rounded out. Partly by me but mainly before I touched it.

Has any one any experience in removing these stubborn bolts, that is the lowest (the most difficult to get at) and right hand top bolt.

My thoughts are drilling the heads out or using a centre punch to hammer the heads around, (could this crack the engine housing where the bolt threads are??) also drilling and using screw extractor.

Any thoughts and advice would be welcome.

[oxidized_black]

they are stubborn. sometimes if you can give them a little bit of a turn tight, it breaks them free. you might have to use heat. they are a pain i know because i removed mine when i tried tightening the oil lines up and it cracked the housing. when i ordered the new housing, i ordered the 3 new bolts too.

[pmnova]

U can try useing an oversize torx bit. Tap it in with a hammer. Ive used this trick working on VWs, they use alot of those bolts

[marioweldinginc]

Agreed the oversized torx trick works alot with rounded allen bolts. Also maybe try an SAE allen head socket that you have to tap in. Also if its available put a dab of valve grinding compund in the bolt head so it wont strip. Not sure how it works but I use it with a 100% success rate.

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[quintain]

Thanks guys

Will try all your tricks, starting with the torx bit, if I have one big enough.

[Getch]

FYI....trick I learned recently with stuck brake bleeder screws. Heat real good, then immediately quench with cold water, then apply the wrench. They loosened right up with very little effort.

Worked great on 2 very stuck bleeders on my car. Unsure if this can/should be used in the oil filter bolts or not for you machine. Mine has a couple wires right there so caution on those with the heat.

[quintain]

Thanks every-one.

2 minutes available today.

I easily undone top right hand bolt using over sized tork "fitted" with a big hammer and it turned off easily.

Didn't have time to get at the difficult bottom bolt so that is for Friday with a bit of luck.

Thanks again for all your interest and excellent advice.

This forum is an excellent source of helpful information from friendly & supportive members.

Thank you again.

[Getch]

FYI...My owners manual does not specifically state this but the service manual does.

Remove the shifter peg and access to that lower allen head is easy. I am new to bikes and thought simply loosening the bolt on the shifter was enough to remove...not the case on the 1990 I have.

Remove the bolt completely and the shifter slips right off.

[quintain]

FYI...My owners manual does not specifically state this but the Service manual does.

Remove the shifter peg and access to that lower allen head is easy. I am new to bikes and thought simply loosening the bolt on the shifter was enough to remove...not the case on the 1990 I have.

Remove the bolt completely and the shifter slips right off.

Thanks Getch

Will do as you say.

Regards

[oxidized_black]

FYI...My owners manual does not specifically state this but the Service manual does.

Remove the shifter peg and access to that lower allen head is easy. I am new to bikes and thought simply loosening the bolt on the shifter was enough to remove...not the case on the 1990 I have.

Remove the bolt completely and the shifter slips right off.

good point. i did exactly that when i replaced the oil filter housing on my '91 ....

[quintain]

SUCCESS

I had to remove the shift pedal as recommended by Getch (thank you) to fully get at the lowest bolt.

I hammered in the oversize torx but it didn't grab, just turned inside the dratted bolt.

Had a coffee thought of swearing but instead used a centre punch and hammered the bolt head, eventually it turned and I took off the last bolt AND then had another coffee.

But I didn't take any notice of how the filter came out, BTW it was very clean.

I have a new OEM filter and like the original it has a closed end and the other end is open.

I believe the filter should be replaced by placing the open end into the engine, so when it is fitted I see the closed end; is this correct.

[oxidized_black]

yes correct, and congrats on the removal. the bolts from yamaha were under 5 dollars when i replaced mine ...

[marioweldinginc]

Congrats! Sometimes on the filter its says which way it faces. Honda does it

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